The original picture resource should be made in vector format, and then a picture of each resolution is generated based on the following scaled dimensions:
- Extra High Resolution XHDPI:2.0
- High resolution hdpi:1.5
- Medium resolution mdpi:1.0 (Benchmark)
- Low resolution ldpi:0.75
Low-resolution (LDPI) resources are not always required. When you provide high-resolution resources, the system will scale them in half to fit the low-resolution device.
- Extra large screen at least 960DP X720DP
- Large screen at least 640DP X480DP
- Standard screen at least 470DP X320DP
- Small screen at least 426DP X320DP
maintaining density is not relevant because, without it, a UI element (such as a button) looks large on a low-density screen and looks small on a high-density screen. Such a change in density-related dimensions affects the layout and use of the application
- The system adjusts the DP units to the appropriate values for the current screen density
- If necessary, the system adjusts the drawing resources to the appropriate size based on the current screen density, but it is best to provide alternate bitmap resources for different densities
from Android3.2 (API level 13), the above dimension groupings have been deprecated ( small, standard, large, oversized ), and you should use the SW<N>DP configuration qualifier to define the minimum available width for the layout resource. For example, if a multi-pane flat layout requires at least 600DP of screen width, SW600DP should be selected. to ensure that the picture looks best, you should include alternate versions at different resolutions to accommodate different screen densities
